 The tunnel network became obsolete after the French and Indian War.In 1818, the original Lebanon County Courthouse was built over one of its entrance/exit points at North 8th Street and Cumberland Street.In 1825, the section leading into the cellar would have been blocked off by construction of the Union Canal towpath canal that ran and operated just south of Light's Fort near present-day Guilford Street in Lebanon, PA. As late as the 1890s, portions of this tunnel network were still accessible through the basement at Stevens School (present-day Stevens Towers at North 10th Street and Willow Street).